Rice cooking device

Abstract

The present application provides a kind of rice cooking device, it is equipped with the main body with pot storage part, rice cooking pot, cover the open portion of the rice cooking pot and be equipped with one or more steam exhaust hole of the steam in the rice cooking pot is discharged when cooking, pot cover and exhaust hood when cooking are closely attached to the periphery of the above-mentioned steam exhaust hole, a preliminary pressure chamber, pressure limiting pipe and connecting pipe are provided inside the exhaust hood, the preliminary pressure chamber is the chamber that temporarily retains the steam from the above-mentioned steam exhaust hole is discharged to the outside of the rice cooking pot, the pressure limiting pipe is the component that the area ratio of the minimum inner diameter is less than the total area of the opening of the above-mentioned steam exhaust hole, the connecting pipe is formed as its inner diameter is greater than the inner diameter of the above-mentioned pressure limiting pipe, the above-mentioned preliminary pressure chamber, the above-mentioned pressure limiting pipe and the above-mentioned connecting pipe are sequentially communicated to constitute a pipeline, and at least one temperature detection unit is installed in the pipeline.

Description

TECHNICAL FIELD

[0001] The present application relates to a rice cooking device, and more particularly, to a commercial pressure type rice cooking device used in a rice cooking factory, a school, a hospital, and the like. BACKGROUND

[0002] At present, a commercial rice cooking device detects the temperature in a pot in order to maintain the quality of cooked rice constant and to perform fire control. A rice cooking device disclosed in Patent Document 1 indirectly detects the temperature in a pot by measuring the temperature of steam discharged from a steam discharge hole of a pot cover.

[0003] The rice cooking device described in Patent Document 1 is provided with an exhaust duct for discharging steam discharged from a rice cooking pot to the outside of a building. The exhaust duct is communicated with an exhaust cover covering a steam discharge hole of a pot cover provided to the rice cooking pot in order to concentrate the steam. The exhaust cover is provided to be rotatable to a set position and a retreat position. Further, the rice cooking device measures the temperature of the exhaust by a temperature sensor installed in the exhaust cover.

[0004] In the rice cooking device of Patent Document 1, a gap is present between the pot cover and the exhaust cover, and thus there is a concern that ambient air of the rice cooking device flows into the exhaust cover from the gap. The temperature sensor measures the temperature of the steam mixed with the ambient air.

[0005] That is, the temperature of the ambient air can be considered as the temperature in the building such as a rice cooking factory, and thus is affected by the temperature difference of seasons or day and night. Therefore, the temperature sensor measures the temperature of the steam in the pot mixed with the ambient air in the building. Thus, in the rice cooking device, it is difficult to accurately measure the temperature of the steam in the pot discharged from the pot cover.

[0006] Therefore, it is strongly desired to develop a method for detecting the temperature of the steam in the pot which is not affected by the ambient air around the rice cooking device.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT DOCUMENTS

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 10-262821 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] In view of the above-described problems, it is an object of the present application to accurately measure the temperature of the steam in the pot discharged from the pot cover in a rice cooking device.

[0012] MEANS OF SOLVING THE PROBLEMS

[0013] The present application provides the following technical solutions, which is a cooking device, which has: a main body having a pot receiving portion on the upper surface; a cooking pot which is freely removable from the main body and into which food is placed; a pot cover which covers the opening of the cooking pot and is provided with one or more steam discharge holes for discharging steam in the cooking pot during cooking; and an exhaust hood which is in close contact with the periphery of the steam discharge hole during cooking, and is provided with a preliminary pressure chamber, a pressure limiting pipe and a connecting pipe on the inside of the exhaust hood, the preliminary pressure chamber is a chamber for temporarily retaining steam discharged from the steam discharge hole to the outside of the cooking pot, the pressure limiting pipe is a component with a minimum inner diameter area smaller than the total opening area of the steam discharge hole, the connecting pipe is formed with an inner diameter larger than that of the pressure limiting pipe, the preliminary pressure chamber, the pressure limiting pipe and the connecting pipe are sequentially communicated to form a pipeline, and at least one temperature detection unit is installed in the pipeline.

[0014] In addition, in the present application, the following technical solutions can be provided: the pot cover has a pressing surface on the upper surface for the exhaust hood to be in close contact with, and the steam discharge hole is arranged at the center of the pressing surface.

[0015] Further, in the present application, the following technical solutions can also be provided: the temperature detection unit is installed in the pipeline of the connecting pipe and near the communication part of the pressure limiting pipe.

[0016] Further, in the present application, the following technical solutions can also be provided: the pressure limiting pipe has an opening communicating with the preliminary pressure chamber arranged downward, and an opening communicating with the connecting pipe arranged upward, and the temperature detection unit is installed at a position directly above the opening.

[0017] Further, in the present application, the following technical solutions can also be provided: the preliminary pressure chamber has a shape with a wide opening communicating with the pot cover and a narrow opening communicating with the pressure limiting pipe, and the shape is tapered from the opening communicating with the pot cover to the opening communicating with the pressure limiting pipe.

[0018] Further, in the present application, the following technical solutions can also be provided: the detection part of the temperature detection unit is in a rod shape, and the long edge direction of the detection part is installed in parallel with the long edge direction of the connecting pipe.

[0019] Furthermore, in the present application, the following technical solutions can also be provided: the temperature detection unit is detachable from the exhaust hood.

[0020] Effects of the invention

[0021] According to the rice cooking device of the present application, an exhaust cover provided for recovering steam discharged from a rice cooking pot during cooking is closely attached to the upper surface of a lid of the rice cooking pot. At this time, the exhaust cover is installed closely around a steam discharge hole provided in the lid, so that ambient air around the rice cooking device does not flow into the exhaust cover. Therefore, the temperature of steam just discharged from the rice cooking pot can be more accurately measured by a temperature detecting unit.

[0022] In addition, according to an embodiment of the present application, a pressing surface for closely attaching the exhaust cover is provided on the lid for the purpose of preventing ambient air around the rice cooking device from flowing into the exhaust cover, and the exhaust cover is pressed and closely attached to the pressing surface. Therefore, according to this embodiment, the steam can be reliably prevented from flowing into the exhaust cover.

[0023] In addition, according to another embodiment of the present application, the temperature detecting unit is provided in the pipe of the connecting pipe and in the vicinity of the communication portion of the pressure limiting pipe, so that the temperature detecting unit can measure the temperature of steam just passing through the pressure limiting pipe. Therefore, according to this embodiment, the temperature of steam in the rice cooking pot can be accurately detected.

[0024] In addition, according to still another embodiment of the present application, the temperature detecting unit is installed directly above the upper opening of the pressure limiting pipe, so that the temperature detecting unit can measure the temperature of steam just passing through the pressure limiting pipe. Therefore, according to this embodiment, the temperature of steam in the rice cooking pot can be accurately detected.

[0025] In addition, when the cooking water in the rice cooking pot boils, the pressure in the rice cooking pot rises, and steam is forcibly discharged from the pressure limiting pipe through the steam discharge hole and the preliminary pressure chamber. The temperature detecting unit directly contacts the forcibly discharged steam. Therefore, according to this embodiment, dirt is difficult to adhere to the surface of the temperature detecting unit. Even if dirt adheres, the surface of the temperature detecting unit can be cleaned by the flow of steam.

[0026] In addition, according to still another embodiment of the present application, the preliminary pressure chamber has a shape in which the opening communicating with the lid is wide and the opening communicating with the pressure limiting pipe is narrow, and the opening communicating with the lid is tapered toward the opening communicating with the pressure limiting pipe. Therefore, according to this embodiment, steam discharged from the steam discharge hole can smoothly flow without stagnation toward the opening communicating with the pressure limiting pipe. In addition, the preliminary pressure chamber has a structure in which dirt and the like are difficult to adhere by the flow of steam.

[0027] In addition, according to still another embodiment of the present application, the detection portion of the temperature detection unit is formed in a rod shape, and is installed in the connection pipe in a manner that the longitudinal direction of the detection portion is parallel to the longitudinal direction of the connection pipe. Therefore, according to this embodiment, the detection portion is parallel to the direction in which the steam flows in the connection pipe, and thus does not hinder the flow of the steam. Moreover, this embodiment provides an installation method in which dirt is less likely to adhere to the detection portion.

[0028] In addition, according to still another embodiment of the present application, the temperature detection unit is detachably installed in the exhaust cover. If maintenance such as replacement is considered, the temperature detection unit is detachably installed, and thus a very beneficial effect can be obtained for the user of the rice cooking device. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a perspective view of an embodiment of the rice cooking device of the present application.

[0030] Figure 2 is a plan view of the rice cooking device according to the embodiment shown in Figure 1

[0031] Figure 3 is a perspective view of the rice cooking pot and the pot cover used in the rice cooking device according to the embodiment shown in Figure 1

[0032] Figure 4 is a side view of the rice cooking pot and the pot cover used in the rice cooking device according to the embodiment shown in Figure 1

[0033] Figure 5 is a perspective view of the sealing device provided in the rice cooking device according to the embodiment shown in Figure 1

[0034] Figure 6 is a schematic partial cross-sectional view of the rice cooking device according to the embodiment shown in Figure 1

[0035] Figure 7 is a view showing that the rotating arm is rotated to the avoidance position in the rice cooking device according to the embodiment shown in Figure 1

[0036] Figure 8 is a view for explaining a configuration example of the rotating unit provided in the rice cooking device of the present application.

[0037] Figure 9 is a view showing a rice cooking model of the embodiment of the rice cooking device of the present application by a graph.

[0038] In the drawings:

[0039] ​​​​​​1 - rice cooking device, 2 - main body, 3 - rice cooking pot, 4 - pot cover, 5 - sealing device, 6 - preliminary pressurizing chamber, 7 - cylinder, 8 - rotating arm, 9 - cylinder mounting table, 10 - side wall, 11 - cylinder, 12 - upper clamping arm, 13 - lower clamping arm, 14 - block main body, 15 - gasket, 16 - rotating roller, 17 - rotating roller, 18 - extension rod, 19 - anti-rotation rod, 20 - pressing surface, 21 - steam discharge hole, 22 - block main body, 23 - positioning roller, 24 - flange, 25 - flange, 26 - sealing gasket, 27 - upper end portion, 28 - exhaust hood, 29 - extension rod, 30 - support table, 31 - anti-rotation rod, 32 - O-ring, 33 - pressure limiting pipe, 34 - steam discharge pipe, 35 - discharge valve, 36 - safety valve, 37 - rotating unit, 38 - shaft cover, 39 - rotating shaft, 41 - cylinder, 42 - fixing plate, 43 - fixing shaft, 44 - rod, 45 - pin, 46 - curved arm, 47 - speed regulator, 48 - speed regulator, 49 - discharge pipe. DETAILED DESCRIPTION

[0040] Hereinafter, an embodiment of the present application will be described in detail with reference to the drawings. Figure 1 is a perspective view showing a rice cooking device 1 of the present application, Figure 2 is a plan view of the rice cooking device 1. Figure 3 and Figure 4 is a view showing a rice cooking pot 3 used in the rice cooking device 1 and a pot cover 4 for covering an opening portion of the rice cooking pot 3.

[0041] The rice cooking device 1 can be used alone as a single rice cooking device. Also, the rice cooking device 1 can be used, for example, as one of a plurality of rice cooking devices of a rice cooking device group of a commercial rice cooking device as described in Patent Document 1. Figure 1

[0042] The rice cooking device 1 is configured to include a main body 2 having a heating unit for heating a rice cooking pot 3 and a housing portion for housing the rice cooking pot 3. The above-mentioned heating unit can be adopted in various ways, and in the present embodiment, a publicly known surface combustion burner is used, and a gas supply pipe (not shown) for supplying a mixed gas of fuel gas and air is connected to a combustion portion of the burner.

[0043] Further, Figure 1 and Figure 2 shows a state in which the rice cooking pot 3 having the opening portion covered by the pot cover 4 is housed in the housing portion of the main body 2.

[0044] ​The main body 2 is provided with a plurality of sealing devices 5 for sealing the cooking pot 3 and the pot cover 4 during cooking. In addition, the main body 2 is provided with a steam recovery portion 50 having an exhaust cover 28 for recovering steam discharged from the steam discharge hole 21 of the pot cover 4, a cylinder 7 for raising and lowering the exhaust cover 28, and a rotating arm 8 for rotating the cylinder 7 in the horizontal direction. Furthermore, a preliminary pressurizing chamber 6 for storing steam is provided inside the exhaust cover 28 (see Figure 6 ).

[0045] Figure 5 is a perspective view of the sealing device 5. The sealing device 5 is provided for sealing the opening of the cooking pot 3 by the pot cover 4 during cooking. The sealing device 5 is provided with a cylinder mounting table 9 via which the sealing device 5 is fixed to the main body 2 by screws or the like. A cylinder 11 is mounted in the side wall 10 of the cylinder mounting table 9, and a support table 14 is mounted at the front end of the extension rod 18 of the cylinder 11. Furthermore, a substantially U-shaped block body 22 is mounted with a gasket 15 sandwiched between the support table 14.

[0046] In addition, a rotating free positioning roller 23 is provided in the cylinder mounting table 9 as a positioning unit when the cooking pot 3 is stored in the main body.

[0047] In addition, the cylinder 11 has a speed regulator 47, and is connected to an air compressor (not shown) via a gas pipe and an electromagnetic valve.

[0048] A clamping arm for clamping the flange 25 of the cooking pot 3 and the flange 24 of the pot cover 4 is formed on the front surface of the substantially U-shaped block body 22. That is, an upper clamping arm 12 is formed on the upper portion of the front surface of the block body 22, and a lower clamping arm 13 is formed on the lower portion of the front surface. Furthermore, rotating free rotating rollers 16 and 17 are respectively mounted on the front ends of the upper and lower clamping arms 12 and 13 in parallel to the horizontal direction. In addition, the substantially U-shaped block body 22 is capable of advancing and retreating in the front and back directions by the extension rod 18 of the cylinder 11. The cylinder 11 also has an anti-rotation rod 19 for preventing rotation of the substantially U-shaped block body 22 when it advances and retreats.

[0049] When the block body 22 clamps the flange 24 of the pot cover 4 and the flange 25 of the cooking pot 3, the block body 22 advances forward (arrow a) by the extension of the extension rod 18 of the cylinder 11, and the rotating rollers 16 and 17 respectively mounted on the upper and lower clamping arms 12 and 13 clamp and press the flanges 24 and 25. By this pressing, the standing upper end portion 27 of the cooking pot 3 (see Figure 5 , Figure 3 , Figure 4 ) is pressed against the sealing gasket 26 provided inside the flange 24 of the pot cover 4, whereby the cooking pot is sealed.

[0050] In the present embodiment, as Figure 1 ,Figure 2 The four sealing devices 5 are arranged at equal intervals around the outer periphery of the rice cooker 3 as shown. However, the number of the sealing devices 5 arranged is not limited to four, and the number of the sealing devices 5 arranged can be increased or decreased depending on the pressurization conditions during cooking. For example, in a case where it is necessary to make the pressure inside the rice cooker high, the number of the sealing devices 5 arranged can be increased. Conversely, in a case where it is not necessary to make the pressure inside the rice cooker so high, the number of the sealing devices 5 arranged can be decreased.

[0051] The rice cooker 3 of the present embodiment is a round pot, and the rice cooker 3 and the pot lid 4 are substantially the same diameter. The pressing surface 20 provided in the central portion of the pot lid 4 is formed as a flat surface (plane). An exhaust cover 28 (indicated by a broken line circle E) of a steam recovery portion 50 is arranged on the upper portion of the pressing surface 20 so as to be detachable with respect to the pressing surface 20. Figure 3 The position indicated by the broken line circle E is provided with one or more steam discharge holes 21 that pass through both faces of the pot lid 4.

[0052] Figure 6 is a partial cross-sectional view of the rice cooking device 1 during pressurized cooking, showing a state in which the exhaust cover 28 of the steam recovery portion 50 is pressed onto the pressing surface 20 by the air cylinder 7. In order to adjust the pressure inside the rice cooker 3, a preliminary pressurization chamber 6 is provided inside the exhaust cover 28. The preliminary pressurization chamber 6 is formed inside the cylindrical exhaust cover 28. The exhaust cover 28 is raised and lowered by the air cylinder 7.

[0053] The air cylinder 7 is attached to a rotary arm 8 that rotates freely. The air cylinder 7 has a speed regulator 48, and is connected to an air compressor (not shown) via a gas pipe and a solenoid valve. In addition, the exhaust cover 28 is attached to a support table 30 at the front end of an extension rod 29.

[0054] Furthermore, the steam recovery portion 50 is also provided with an anti-rotation rod 31 that prevents the exhaust cover 28 from rotating when it is raised and lowered.

[0055] During cooking, the exhaust cover 28 is pressed onto the pressing surface 20 of the pot lid 4 by the air cylinder 7. At this time, an annular O-ring 32 attached to the bottom surface of the exhaust cover 28 is pressed against the planar pressing surface 20.

[0056] During cooking, steam flows into the preliminary pressurization chamber 6 of the exhaust cover 28 from the steam discharge holes 21, and the steam that flows in is discharged outside the device from a pressure-limiting pipe 33 provided above the preliminary pressurization chamber 6.

[0057] However, the opening area of the pressure-limiting pipe 33 is set to be smaller than the total opening area of the steam discharge holes 21. Therefore, during the continuous boiling process during cooking, only a portion of the steam that flows into the preliminary pressurization chamber 6 is discharged outside the device. The steam that is not discharged is compressed and stored inside the preliminary pressurization chamber 6. Therefore, the pressure inside the preliminary pressurization chamber 6 gradually rises. In turn, the pressure inside the rice cooker 3 also rises.

[0058] In the present embodiment, the pressure-limiting tube 33 is a tubular member having a diameter of about 3 mm and a length of about 4 mm. The preliminary pressure chamber 6 is formed so that the opening on the side (the inlet) that is in contact with the pressing surface 20 is larger than the opening on the side (the outlet) that communicates with the pressure-limiting tube 33. In the preliminary pressure chamber 6 of the present embodiment, the opening on the side (the inlet) that is in contact with the pressing surface 20 is disposed toward the lower side, and the opening on the side that communicates with the pressure-limiting tube 33 is disposed toward the upper side. Further, the preliminary pressure chamber 6 is tapered from the lower side toward the upper side. The shape of the preliminary pressure chamber 6 is preferably a main body, and particularly desirably a circular cone.

[0059] Further, the total opening area of the steam discharge hole 21 refers to the area of one steam discharge hole 21 in the case where the steam discharge hole is provided with only one steam discharge hole 21. On the other hand, in the case where a plurality of steam discharge holes 21 are provided, the total opening area of the steam discharge hole 21 refers to the sum of the areas of the plurality of steam discharge holes 21.

[0060] Therefore, even in the case where the diameter of one steam discharge hole 21 is smaller than the diameter of the pressure-limiting tube 33, by providing a plurality of steam discharge holes 21, it is possible to make the total opening area of the steam discharge hole 21 larger than the opening area of the pressure-limiting tube 33.

[0061] The connection tube 34 provided to the exhaust hood 28 is a tube that communicates with the outlet side of the pressure-limiting tube 33. In the present embodiment, a configuration is provided in which steam is discharged from the connection tube 34 to a predetermined position outside the device via the discharge tube 49. The discharge tube 49 can also be provided with a discharge valve 35 that adjusts the discharge described above.

[0062] Further, in order to smoothly discharge the steam, the inner diameter of the connection tube 34 is larger than the inner diameter of the pressure-limiting tube 33, and by this structure, it is possible to smoothly discharge the steam outside the device.

[0063] In addition, in the case where the pressure in the preliminary pressure chamber 6 becomes abnormally high, a safety valve (not shown) can also be provided to the exhaust hood 28.

[0064] The detection portion 52 of the temperature detection unit 51 is installed in the connection tube 34. The temperature detection unit 51 is installed by being inserted into the detection portion 52 from the outside of the exhaust hood 28. As the method of installing the temperature detection unit 51, there are a method in which a screw portion is provided to the temperature detection unit 51 and screwed into a threaded hole provided to the side surface of the exhaust hood 28, a method in which the temperature detection unit 51 is fixed by screwing in a state in which it is inserted into the exhaust hood 28, and the like. If maintenance of the temperature detection unit 51 is taken into consideration, it is preferable that the temperature detection unit 51 be configured to be detachable from the exhaust hood 28.

[0065] In the illustrated example, the detection unit 52 is rod-shaped and is installed inside the connecting pipe 34 such that the long side of the detection unit 52 is parallel to the long side of the connecting pipe 34. Furthermore, the mounting location for the detection unit 52 is preferably near the junction of the pressure limiting pipe 33 and the connecting pipe 34. Particularly preferred is that it can be installed as follows... Figure 6 As shown, the detection unit 52 is installed directly above the outlet side opening of the pressure limiting tube 33.

[0066] A signal line (not shown) is connected to the temperature detection unit 51 to transmit the temperature-related signal detected by the detection unit 52 to the control device 60 (not shown). This signal line is preferably wired along the rotating arm 8.

[0067] However, the installation location of the temperature detection unit 51 is not limited to inside the connecting pipe 34, but can also be inside the pre-pressurization chamber 6 or the pressure limiting pipe 33.

[0068] In this embodiment, the diameter of the lower opening of the pre-pressurization chamber 6 is set to 50 mm, the diameter of the upper opening is set to 5 mm, and the height is set to 19 mm. Preferably, the upper opening is set to have the same diameter as the connected pressure limiting tube 33.

[0069] In addition, the diameter of the steam vent 21 is approximately 5 mm. The diameter of the pre-pressurization chamber 6 needs to be set to cover all the multiple steam vents 21 provided.

[0070] The diameter of the pressure limiting tube 33 is not limited to 5 mm and can be appropriately determined experimentally based on the cooking conditions. Furthermore, the shorter the length of the pressure limiting tube 33, the better; preferably 10 mm or less, more preferably 6 mm or less, and in this embodiment, 4 mm. The reason for the shorter length of the pressure limiting tube 33 is that steam generated from the rice cooker 3 may mix with impurities such as rice water (sticky substances produced during cooking), seasonings, etc., thus raising concerns that the pressure limiting tube 33 may become clogged by these impurities.

[0071] The rotating arm 8, equipped with the exhaust hood 28, is designed to rotate horizontally via the rotating unit 37 described later. During cooking, the rotating arm 8 rotates to a position where the exhaust hood 28 is positioned directly above the steam vent 21 located in the center of the pot lid 4. On the other hand, when the rice cooker 3 is moved in and out, as... Figure 7 As shown, the rotating arm 8 rotates to the position to be avoided.

[0072] The rotating unit 37 in this embodiment is configured to include: a shaft cover 38 erected on the upper surface 40 of the main body 2 (see reference). Figure 1 ); a rotating shaft 39 rotatably disposed within the shaft cover 38 via a bearing; and a cylinder 41 connected to the lower end of the rotating shaft 39 inside the main body 2 (see reference). Figure 8 ).

[0073] Figure 8 Fig. 18 is a view for explaining the structure and operation of the rotating unit 37, and is a view showing the rotating unit 37 from below the rice cooking device 1. The shaft cover 38 and the rotating shaft 39 are extended to the inside of the main body 2. The shaft cover 38 is fixed to a fixed plate 42 provided in the inside of the main body 2. One end of the air cylinder 41 is pivotally fixed to a fixed shaft 43, and the front end of a rod 44 at the other end is connected to one end of a bent arm 46 via a pin 45. The other end of the bent arm 46 is fixed to the lower end of the rotating shaft 39.

[0074] The rotating unit 37 is thus constructed, so that when the rod 44 of the air cylinder 41 is advanced and retracted, the pin 45 serves as a fulcrum, the rotating shaft 39 rotates, and the rotating arm 8 horizontally rotates. In addition, the rotating unit 37 can use a rotating unit such as a motor.

[0075] Next, the operation and effect of the rice cooking device 1 employing the above-described structure will be described.

[0076] First, the user of the rice cooking device 1 himself / herself or using an arbitrary feeding unit feeds an appropriate amount of rice and rice cooking water into the rice pot 3, respectively. Then, the user himself / herself or using an arbitrary pot cover unit covers the opening of the rice pot 3 with the pot cover 4 and performs a soaking process. After the soaking process, the user himself / herself or using an arbitrary conveying unit conveys the rice pot 3 to the pot storage portion of the rice cooking device 1.

[0077] In addition, the user can perform the soaking process while the rice pot 3 is stored in the pot storage portion of the rice cooking device 1, or can convey an empty rice pot to the rice cooking device 1 and then feed rice and rice cooking water into the conveyed rice pot 3.

[0078] In addition, after the soaking, a stirring process for stirring the inside of the rice pot 3 is desirably provided. In addition, depending on the kind of the steamed rice, the user sometimes feeds seasonings and ingredients into the rice pot 3.

[0079] When the rice pot 3 is conveyed to the rice cooking device 1, the plurality of sealing devices 5 operate, and the rice pot 3 is sealed by the pot cover 4 by the rotating rollers 16 and 17. The extension rod 18 of the air cylinder 11 is extended by a signal from a control device 60 not shown, and the rotating rollers 16 and 17 provided at the front end of the extension rod 18 grip the flange 25 of the rice pot 3 and the flange 24 of the pot cover 4 overlapped on the flange 25, thereby achieving the sealing of the rice pot 3.

[0080] Then, the rotating arm 8 in the retracted position is horizontally rotated by the rotating unit 37, and the exhaust cover 28 attached to the front end portion of the rotating arm 8 is moved directly above the pressing surface 20 of the pot cover 4. After the movement, the extension rod 29 of the air cylinder 7 is extended downward, and the bottom surface of the exhaust cover 28 is pressed against the pressing surface 20.

[0081] Then, in the state where the exhaust hood 28 is pressed against the pressing surface 20, heating of the rice cooker 3 by the heating unit is started. The heating is performed in accordance with a predetermined rice cooking program.

[0082] Figure 9 is a graph showing an example of a rice cooking program of the rice cooking apparatus 1 according to the present embodiment, and shows the temperature of steam discharged from the rice cooker 3 and the heating program during rice cooking, with the horizontal axis representing time and the vertical axis representing the temperature of steam detected by the temperature detecting unit 51 (°C) and the heating output of the heating unit (%).

[0083] In this example, 7 kg of white rice is soaked for 70 minutes and then cooked. As shown in the graph, after the start of cooking, the first temperature raising process (time until the temperature in the rice cooker becomes 100°C) is performed for 10 minutes and 40 seconds, the boiling maintenance process is performed for 2 minutes and 40 seconds from 10 minutes and 40 seconds to 12 minutes and 40 seconds, and then the second temperature raising process is performed for 3 minutes from 12 minutes and 40 seconds to 15 minutes. Figure 9

[0084] In the first temperature raising process performed after the start of cooking, the temperature of steam discharged from the rice cooker 3 continuously rises to 100°C. During this period, the temperature of the cooking water has not reached the boiling point, and therefore steam is not substantially generated in the rice cooker. Thus, the pressure in the rice cooker does not change. When the temperature reaches 100°C and the cooking water in the rice cooker 3 boils, steam is generated in large quantities, and a portion of the steam flows into the preliminary pressure chamber 6 from the steam discharge hole 21 provided in the pressing surface 20 of the lid 4.

[0085] The steam flowing into the preliminary pressure chamber 6 is discharged to the outside of the apparatus via the pressure limiting pipe 33. In the embodiment according to the present invention, the opening area of the pressure limiting pipe 33 is smaller than the total opening area of the steam discharge hole 21.

[0086] Thus, the amount of steam discharged from the preliminary pressure chamber 6 is smaller than the amount of steam flowing into the preliminary pressure chamber 6, and therefore the steam flowing from the rice cooker 3 into the preliminary pressure chamber 6 remains in the preliminary pressure chamber 6.

[0087] During the boiling maintenance process, steam continues to be generated in the rice cooker 3. Along with this, the amount of steam flowing into and remaining in the preliminary pressure chamber 6 increases. As a result, the pressure in the preliminary pressure chamber 6 exceeds atmospheric pressure and gradually rises.

[0088] Along with this, the pressure in the rice cooker 3 also rises. During the boiling maintenance process, the pressure in the rice cooker continues to rise, and in the embodiment according to the present invention, eventually rises to 1.24 atm.

[0089] ​At the end of the boiling maintenance process, the cooking water in the rice cooker 3 has a portion absorbed by the rice and a portion evaporated into steam. In the subsequent heating process, the amount of cooking water is negligible. The pressure inside the rice cooker 3 gradually decreases.

[0090] When multiple rice cookers are used to heat a large quantity of rice, it is essential to ensure uniform quality of the rice cooked by each cooker. To prevent this quality from varying, the heating model from the moment the cooking water boils and the pot temperature reaches 100°C must be identical in each cooker. Therefore, it is crucial to accurately time the temperature inside the pot of each cooker to reach 100°C.

[0091] In an embodiment of the invention with an inherent structural design, this detection is performed by a temperature detection unit 51. The temperature inside the pot is obtained based on the temperature of the steam measured by the temperature detection unit 51.

[0092] In this embodiment, the pre-pressurization chamber 6 is pressurized to above atmospheric pressure during cooking. Steam discharged from the rice cooker 3 is discharged to the outside of the device via the pressure limiting pipe 33, connecting pipe 34, discharge valve 35, and discharge pipe 49, due to the pressure in the pre-pressurization chamber 6. Therefore, it is not necessary to provide a separate suction device for the rice cooking device 1 to discharge the steam to a predetermined location such as outdoors.

[0093] Furthermore, if the heating model (heating cycle) of the heating unit is explained, then as follows: Figure 9 As shown, from the start of cooking rice to 10 minutes and 40 seconds, the output of the surface combustion burner of the heating unit is set to 75%; from 10 minutes and 40 seconds to 12 minutes and 40 seconds, the output is set to 40%; and from 12 minutes and 40 seconds to 15 minutes, the output is set to 30%.

[0094] Furthermore, in this embodiment, the exhaust hood 28 is pressed against the pressing surface 20, and an annular O-ring 32 is provided on the bottom surface of the exhaust hood 28. Therefore, steam will not leak from the contact surface between the exhaust hood 28 and the pressing surface 20. Moreover, the pressing force required to press the exhaust hood 28 against the pressing surface 20 must be such that it will not cause steam leakage. Therefore, the cylinder 7 needs to be selected with consideration for the required pressing force to obtain the desired pressing force.

[0095] After the second temperature raising step, a post-cooking step such as simmering is performed. The simmering can be performed in a state where the cooking pot 3 is stored in the cooking device 1, but is generally performed at another place after the cooking pot 3 is carried out from the cooking device 1. When the cooking pot 3 is taken out from the cooking device 1, first, the exhaust hood 28 is raised by the cylinder 7, and the rotary arm 8 is moved to the standby position by the rotation unit 37. Then, the steam remaining in the cooking pot 3 is discharged to the outside of the pot from the steam discharge hole 21 of the pot lid 4 without being limited by the pressure limiting pipe 33, and the pressure in the cooking pot 3 is sufficiently reduced, and then the pot 3 is released from the sealing by the fixing unit 5. Further, the time until the exhaust hood 28 is raised and the sealing is released is about 30 seconds.

[0096] According to the present embodiment, the steam generated in the cooking pot 3 must be discharged to the outside of the device via the pressure limiting pipe 33 of the preliminary pressure chamber 6 provided in the exhaust hood 28. That is, the pressure in the cooking pot 3 is regulated by the pressure limiting pipe 33. Further, in the case where the cooking pot is pressurized, it is preferable that the cooking device 1 is configured in such a manner that the value of the pressure in the pot can be regulated by the diameter of the pressure limiting pipe 33 according to the quality of the rice that is targeted, and more specifically, the value of the pressure in the pot can be regulated in the range of 1.1 to 1.4 atmospheres. Further, the cooking device 1 can also be configured in such a manner that the regulation of the value of the pressure in the pot is performed only by changing the diameter of the pressure limiting pipe 33.

Claims

1. A rice cooking apparatus, characterized by comprising: Possessing: a main body having a pot housing portion on an upper surface; a cooking pot which is freely inserted into and withdrawn from the main body and into which a food to be cooked is put; a pot cover which covers an opening portion of the cooking pot and is provided with one or more steam discharge holes through which steam in the cooking pot is discharged during cooking; and an exhaust cover which is in close contact with the periphery of the steam discharge hole during cooking, a preliminary pressure chamber, a pressure limiting pipe, and a connecting pipe are provided inside the exhaust cover, the preliminary pressure chamber is a chamber in which steam discharged from the steam discharge hole to the outside of the cooking pot is temporarily retained, the pressure limiting pipe is a member whose area ratio of the minimum inner diameter to the total area of the opening of the steam discharge hole is small, the connecting pipe is formed to have a larger inner diameter than that of the pressure limiting pipe, the preliminary pressure chamber, the pressure limiting pipe, and the connecting pipe are connected in series to form a pipe line in which at least one temperature detecting unit is installed, the pressure limiting pipe is provided with an opening communicating with the preliminary pressure chamber downward and an opening communicating with the connecting pipe upward, and the temperature detecting unit is installed at a position directly above the opening communicating with the connecting pipe.

2. The cooking device according to claim 1, characterized in that: the pot cover is provided with a pressing surface on which the exhaust cover is in close contact on an upper surface, and the steam discharge hole is disposed at a central portion of the pressing surface.

3. The cooking device according to claim 1 or 2, characterized in that: the temperature detecting unit is installed in the pipe line of the connecting pipe and in the vicinity of the communicating portion with the pressure limiting pipe.

4. The cooking device according to claim 1 or 2, characterized in that: the preliminary pressure chamber is shaped such that the opening communicating with the pot cover is wide and the opening communicating with the pressure limiting pipe is narrow, and is tapered from the opening communicating with the pot cover toward the opening communicating with the pressure limiting pipe.

5. The cooking device according to claim 1 or 2, characterized in that: the detecting portion of the temperature detecting unit is shaped like a rod, and is installed with the long side direction thereof parallel to the long side direction of the connecting pipe.

6. The cooking device according to claim 1 or 2, characterized in that: the temperature detecting unit is detachably attached to the exhaust cover.

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